Field of the Invention
The present invention relates to a dielectric composition, which is particularly suitable for being used in a high-temperature condition such as one for automotive use; and an electronic component in which the dielectric composition is used as a dielectric layer.
Priority is claimed on Japanese Patent Application No. 2016-153013 and Japanese Patent Application No. 2016-153014 filed Aug. 3, 2016, both of which were filed on Aug. 3, 2016, the contents of which are incorporated herein by reference.
Description of Related Art
The laminated ceramic capacitors are mounted on many electronic devices because of their high reliability and low cost. Specific examples of electronic devices include information terminals such as cellular phones, home appliances, and automobile electrical components. Among them, in laminated ceramic capacitors used for automotive use, guarantee is required to a higher-temperature range compared to the laminated ceramic capacitor used for home appliances, information terminals, or the like. In order to retain their functions, high insulation properties are required.
Moreover, in laminated ceramic capacitors for surge voltage removal, which are expected to be used in the high temperature range at 150° C. or more and mounted on the inverter circuit using the power semiconductors of SiC, GaN or the like, high insulation property is required in the wide range of temperature from the room temperature to at least 200° C., for example, to about 250° C.
In WO 2008/155945 discloses a laminated ceramic capacitor using a dielectric composition, which includes a mixed crystal system of a tungsten bronze structure compound and perovskite structure compound as the main component. The tungsten bronze structure compound is a dielectric ceramic composition that shows a sufficient dielectric constant; and stable capacitance-temperature characteristics and high resistivity ρ can be obtained even at high temperature about 175° C. by using this tungsten bronze structure compound. The tungsten bronze structure compound is expressed by the chemical formula (1-a)(K1-xNax)(Sr1-y-zBayCaz)2Nb5O15-a(Ba1-bCab)TiO3. The dielectric ceramic composition includes the accessory component in 0.1 to 40 mol part per 100 mol part of the above-described main component.
In addition, WO 2008/102608 discloses a dielectric ceramic composition having high resistivity at the room temperature because it includes: the tungsten bronze type complex oxide expressed by the chemical formula (K1-xNax)Sr2Nb5O15 (where 0≤x<0.2) as the main component; and 0.05-20 mol part of a rare-earth element and 0.05-40 mol part of Mn, V, Li or the like, as the accessory component.
Japanese Unexamined Patent Application, First Publication No. 2000-124058 discloses a method for improving high temperature load life of the laminated ceramic dielectric capacitor by including [(Ba1-x-yCaxSry)O]m.(Ti1-zZrz)O2 as the main component and 0.005-0.5 weight % of P2O5 (about 0.5 mol % after being converted to the value in mol %) as the accessory component to the dielectric composition for the dielectric composition to behave as a barrier layer preventing migration of Ni ions in a high temperature load test.